For starting, a starting device for the internal combustion engine having a starter motor is usually coupled to the internal combustion engine in that a starter pinion of the starter motor meshes with a ring gear of the internal combustion engine. For this purpose, the ring gear is situated on a drive shaft of the internal combustion engine.
A start-stop system for a motor vehicle having an internal combustion engine is known to turn off the internal combustion engine at a brief stop of the motor vehicle, e.g., at a red traffic light, and to restart it to continue driving.
Moreover, it is understood to turn off the internal combustion engine by discontinuing the fuel supply, e.g., an injection, and/or an ignition of the fuel; in this case, the internal combustion engine does not stop immediately after being turned off, but coasts in a characteristic manner, namely in a characteristic rotational speed course of the drive shaft which is referred to in the following as coasting. The internal combustion engine has cylinders which each determine the characteristic rotational speed course.
International patent application WO 2009/083477 A1 discusses a method for activating a control unit of a starter of an internal combustion engine to reengage a coasting internal combustion engine for a reflex start. A general slope trend of the coasting rotational speed is calculated from multiple speed points over several cycles.
German patent document DE 10 2008 041 037 discusses a method of a control for a start-stop operation of an internal combustion engine in a motor vehicle for temporarily stopping and starting the internal combustion engine which is started by an electric machine as a starter; for this purpose, the position and the rotational speed of a crankshaft are detected by a detection device during operation and after turning off the internal combustion engine, in particular for a temporary stop. Furthermore, the course of the rotational speed of the crankshaft is calculated in advance at and from characteristic repeating positions, such as dead centers, of the crankshaft actively and anew after turning off the internal combustion engine.